The personal scientific library of Charles Darwin has been made available online for the first time via the Biodiversity Heritage Library – including notes and comments scribbled him on the pages and margins.

These annotated books are now in the process of being digitized. The first phase of this project has just been completed, with 330 of the most heavily annotated books launched online at the Biodiversity Heritage Library for all to read.

Charles Darwin’s Library is a digital edition and virtual reconstruction of the surviving books owned by Charles Darwin. This BHL special collection draws on original copies and surrogates from other libraries. It also provides full transcriptions of his annotations and marks. In total, Darwin’s library amounted to 1480 books, of which 730 contain abundant research notes in their margins. In this first release (2011) 330 of the most heavily annotated books have been made available. To support the project BHL has developed a new facility on the BHL website to feature special collections. http://www.biodiversitylibrary.org/collection/darwinlibrary.

Because Darwin’s evolutionary theory covered so many aspects of nature, reading served him as a primary source of evidence and ideas. Darwin once complained that he had become a ‘machine for grinding general laws out of large collections of facts’.

The pages of Darwin’s Library, smothered as they are in his tantalising scrawl, give us a direct view of the great Darwinian intellectual machine in action. With the Charles Darwin Library online, now everyone can retrace how Darwin systematically used reading to advance his science.

Most of Darwin’s personal library rests at Cambridge University Library and at Down House. Although the majority of the books are scientific, some are humanities texts on subjects that Darwin transformed into scientific topics.

The series of transcriptions accompanying each page allows everyone to see which passages Darwin found relevant to his work, stimulated his thinking, or just annoyed him as he read the work of others.

For example, his friend Charles Lyell wrote in his famous Principles of Geology that there were definite limits to the variation of species. Darwin wrote alongside this: “If this were true adios theory”. See the image below.

Final page of Volume 2 of Lyell’s Principles of Geology (5th edition, 1837). Note the annotation on the left page“If this were true adios theory” (Image from Cambridge University Library)

The online transcribed marginalia relies on the work of two scholars, Mario A. Di Gregorio and Nick Gill, published in the 1990s and now greatly enhanced by Gill. Finally, in addition to images of the books and transcribed jots, the information is fully indexed so that people can search for topics and ideas relevant to their interests or work.